//package editor.cn;
////You are climbing a stair case. It takes n steps to reach to the top.
////
//// Each time you can either climb 1 or 2 steps. In how many distinct ways can yo
////u climb to the top?
////
//// Example 1:
////
////
////Input: 2
////Output: 2
////Explanation: There are two ways to climb to the top.
////1. 1 step + 1 step
////2. 2 steps
////
////
//// Example 2:
////
////
////Input: 3
////Output: 3
////Explanation: There are three ways to climb to the top.
////1. 1 step + 1 step + 1 step
////2. 1 step + 2 steps
////3. 2 steps + 1 step
////
////
////
//// Constraints:
////
////
//// 1 <= n <= 45
////
//// Related Topics 动态规划
//// 👍 1263 👎 0
//
//
////leetcode submit region begin(Prohibit modification and deletion)
//class Solution {
//    public int climbStairs(int n) {
//
//        //斐波那契数列
//        int p = 0, q = 0, r = 1;
//        for (int i = 1; i <= n; ++i) {
//            p = q;
//            q = r;
//            r = p + q;
//        }
//        return r;
//    }
//}
////leetcode submit region end(Prohibit modification and deletion)
